This kind of apparatus for applying an adhesive on mounting positions of electronic components in a circuit board is structured as shown in FIG. 10.
This apparatus is disposed somewhere on a conveying route of a circuit board a, that is, between a loading portion c and an unloading portion d, and comprises:
a table e on which the conveyed circuit board a is set, being capable of moving in a direction at right angle to the conveying direction, PA1 table positioning means f for positioning the table e by moving in the direction at right angle to the conveying direction, PA1 an application head g disposed relatively to the table 3, being capable of applying an adhesive on necessary positions on the circuit board 1 and moving in the conveying direction, and PA1 head positioning means h for positioning the application head g by moving in the conveying direction.
The application positions of the adhesive on the circuit board 1 are scattered about on the horizontal plane of the circuit board a. In order to apply the adhesive on any position, it is necessary to move the table e and the application head g relatively in two directions of the X-axis direction and Y-axis direction mutually orthogonal on the horizontal plane.
In the apparatus shown in FIG. 10, the table e is movable in the direction at right angle to the conveying direction, while the application head g is movable in the conveying direction, thereby satisfying the above conditions. This constitution avoids a large structure allowing to four times of the area of the circuit board a as required in the constitution where only the table e moves in both X-axis direction and Y-axis direction, or only the application head g moves in both X-axis direction and Y-axis direction.
In such apparatus, however, the production efficiency of the electronic circuit board cannot be raised sufficiently, and it is impossible to meet the recent demand for higher speed in the manufacturing line of electronic circuit boards. More specifically, there is a limit in the moving speed of the table e and application head g, or the speed of application work in positioning state corresponding to the application positions.
To satisfy the requirements, by installing two application apparatuses in the conveying direction in the conveying route b, it has been already attempted to apply the adhesive on two circuit boards a simultaneously by using these application apparatuses.
In this constitution, however, the length of the conveying direction occupied by the application apparatuses on the manufacturing line of circuit boards a is twice as long as in the case of single apparatus, and it requires a wide plane space, and workers cannot cross the manufacturing line unless an overhead bridge or other bypass route is provided, and it is very inconvenient for maintenance control of parts of the manufacturing line, and maintenance, supply and other works of circuit boards a, adhesive, and parts required in the manufacturing line.
Accordingly, in the midst of the conveying route b as shown in FIG. 11, a table e for setting two circuit boards a on is provided closely to the conveying direction, two application heads g are integrally coupled, and positioned above the table e so as to move and position, and the adhesive is applied simultaneously to both circuit boards a set on the table e by the application heads g.
By constituting as shown in FIG. 11, the length of the conveying direction occupied in the manufacturing line can be shortened as compared with the case of parallel installation of plural application apparatuses.
In the constitution in FIG. 11, however, two circuit boards a set on one table e cannot be freely positioned individually, and the application heads g are mutually coupled and cannot be moved individually, and hence it is hard to apply adhesive at high precision. In this case, the adhesive may be applied on the land of the circuit pattern formed on the circuit board a, and the electric connection of the mounted electronic component and the land may be defective, and the yield may be lowered.
In the conventional apparatus for applying adhesive shown in FIG. 10, incidentally, a trial application aid 41 for presenting a tape as a trial application by the application head g is provided near the table in the conveying route (see FIG. 1 which shows an embodiment of the invention).
This trial application aid 41 takes up a loaded roll tape 42 on a take-up reel 44 from above a backup material 43, and presents for trial application by the application head g while renewing the tape portion on the backup material 43.
By this trial application, the application head g prevents drying of adhesive at the nozzle tip while the applicator is not in use, and executes normal application of adhesive stably for a long period. The roll tape 42 is a consumable material, and when the roll tape 42 is used up, the application apparatus stops at the tape end, and the roll tape 42 must be replaced with a new one.
The conventional trial application aid 41 moves properly between the working position in which the backup material 43 is at same height as the conveying level of the circuit board a, and the escape position positioned lower than the conveying level of the circuit board a so as not to interfere the conveyance of circuit board a, and it is designed to realize trial application by the application head without disturbing the conveyance of the circuit board a.